| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Portland | 1 | 70,070 | 68,487 | 0.23% | 3,253 | 22 | City |
| South Portland | 2 | 26,979 | 26,576 | -0.1% | 2,240 | 12 | City |
| Scarborough | 3 | 25,054 | 22,223 | 2.07% | 525 | 48 | Town |
| Brunswick | 4 | 23,351 | 21,767 | 1.28% | 499 | 47 | Town |
| Westbrook | 5 | 21,691 | 20,436 | 0.58% | 1,262 | 17 | City |
| Windham | 6 | 20,051 | 18,497 | 0.7% | 430 | 47 | Town |
| Gorham | 7 | 19,895 | 18,356 | 3.41% | 393 | 51 | Town |
| Falmouth | 8 | 13,012 | 12,477 | 0.23% | 443 | 29 | Town |
| Standish | 9 | 11,052 | 10,245 | 0.47% | 187 | 59 | Town |
| Cape Elizabeth | 10 | 9,927 | 9,555 | 1.02% | 668 | 15 | Town |
| Yarmouth | 11 | 9,048 | 8,997 | -0.15% | 675 | 13 | Town |
| Freeport | 12 | 8,973 | 8,735 | 0.44% | 258 | 35 | Town |
| Cumberland | 13 | 8,901 | 8,470 | 0.28% | 389 | 23 | Town |
| Gray | 14 | 8,766 | 8,259 | 1.04% | 202 | 43 | Town |
| Bridgton | 15 | 6,034 | 5,421 | 1.16% | 106 | 57 | Town |
| New Gloucester | 16 | 6,006 | 5,723 | 0.7% | 127 | 47 | Town |
| Harpswell | 17 | 5,124 | 5,023 | 0.43% | 213 | 24 | Town |
| Raymond | 18 | 4,670 | 4,558 | 0% | 141 | 33 | Town |
| North Yarmouth | 19 | 4,472 | 4,101 | 1.08% | 211 | 21 | Town |
| Naples | 20 | 4,186 | 3,929 | 1.41% | 131 | 32 | Town |
| Casco | 21 | 3,814 | 3,639 | 0.93% | 122 | 31 | Town |
| Harrison | 22 | 2,678 | 2,456 | 1.48% | 81 | 33 | Town |
| Sebago | 23 | 2,014 | 1,916 | 0.95% | 61 | 33 | Town |
| Baldwin | 24 | 1,689 | 1,516 | 1.75% | 48 | 35 | Town |
| Pownal | 25 | 1,660 | 1,577 | 0.91% | 73 | 23 | Town |
| Chebeague Island | 26 | 400 | 391 | 0.5% | 112 | 4 | Town |
| Long Island | 27 | 237 | 234 | 0.85% | 165 | 1 | Town |
| Frye Island | 28 | 25 | 24 | 0% | 19 | 1 | Town |
Portland is the largest city in Cumberland County, with a population of 70,070.
Frye Island is the smallest city in Cumberland County, with a population of 25.
There are 28 cities in Cumberland County, Maine.